Power failure alarm

[saxondale]

here you go - off the shelf ( well over the Atlantic )


http://www.amazon.com/Chaney-Wirele...G0E/ref=tag_tdp_sv_edpp_i/104-8614599-5182300

 

[breezer]

Hey Breezer. How about using an old sounder unit with a 12v supply and an SAB? When the power goes off the SAB hold-off will drop out and the sounder will wail?

now that would be a novel idea.

only an alarm cable from shed to house, shed end having a wall wart.

bit loud though..............................

unless




he fixes it to the outside of the shed

 

[Space cat]

Here's an idea that might just work if the shed isn't too far away. You need a wireless baby alarm that works on FM and whose receiver makes a loud hissing noise if it can't find a signal from any transmitter. The hiss is a quirk of FM receivers. It can be muted by clever design but tends not to be in cheap stuff.

Plug the transmitter into a socket in the shed and the receiver anywhere you like in the house. You can even take it with you as you move from room to room. When the shed power is on you'll hear very little, just the quiet humming of the freezer's motor, but if the transmitter goes off you'll get that annoying hissing sound.

NB: This trick won't work if you are within range of somebody else's transmitter on the same frequency. You'll end up listening in on their baby instead of your freezer!

 

[dannyboi2003]

I think using relays etc. is a little OTT for a shed at the bottom of the garden, if it was my house i would do this....

Assuming the shed is supplied from its own circuit breaker in the house consumer unit, i would install a single socket along side the consumer unit fed from this same circuit (clearly labelled to avoid confusion) and i would plug one of these into it http://www.maplin.co.uk/module.aspx?ITAG=FAQ&ModuleNo=98632&doy=3m11#faq

Then if the circuit breaker trips for whatever reason cutting the power to the shed, it will also cut the power to the socket which will then cause the alarm to sound. Anyone in the house would hear the alarm and reset the breaker assuming there isn't a more serious fault on the circuit.

A very simple and cost effective solution, and as your adding the socket to an existing circuit (hopefully in a non special location) you wouldn't need to worry about part p. I should also point out that if the shed is supplied by say a 6mm cable with a 32amp breaker in the house CU then the socket should also be wired up using 6mm T&E, a good quality socket such as MK or Crabtree will accept a 6mm cable.

All the best
Dan

 

[JOHNBOY42]

dannyboi2003.........cheers,this is just what I am looking for...some of the other info was good but I like the simple plug and play enviroment and its quite cheap

 

[AlanE]

I have got a fused feed in the shed at the bottom of the garden with a freezer in it and last week the fuse tripped and the freezer was off but it only must have been a few hours ...now what Ineed is some type of alarm to let me know when this happens so the freezer does not be off for days without noticing.

Above is the original post and assuming that the fuse that tripped was in the shed down the garden how will the smart plug help?? It's still got its power supply!

 

[dannyboi2003]

My idea was purely based on the assumption that the circuit breaker that tripped was in the house CU, if the shed has its own CU and this is the trip that failed then i agree this solution would not be of much use. As i say it was an assumption but the OP seemed pleased with my suggestion.

All the best
Dan

 

[Steve]

Whatever solution is used, piggyback it into the same plug top as the freezer (or use a glanded JB on the freezer's flex)! Then if the plug fuse blows, you'll know!

A better alternative, and one which is widely used commercially, is a temperature monitor. These are expensive. They are normally set to alarm when the temp goes above -10 for, say, half an hour. And again, how do you get to know in the house.

I think using relays etc. is a little OTT for a shed at the bottom of the garden,

Depends how much you value the contents of the freezer surely. If you have a whole cow in there, I dont think you'd want to fart about disposing of its rotting dead ass when your freezer goes down!

 

[dannyboi2003]

Depends how much you value the contents of the freezer surely. If you have a whole cow in there, I dont think you'd want to fart about disposing of its rotting dead ass when your freezer goes down!

Fair point.

Scurries off an hides in corner while sucking thumb.

 

[breezer]

The other thing to consider is, even if it has a power failure alarm, what happens if you are out all day at work?

 

[plugwash]

I was under the impresison thant a good quality freezer left unopened should hold it's temperature for long enough for that not to be a problem.

 

[saxondale]

Steve

http://www.amazon.com/Chaney-Wireless-Digital-Refrigerator-Thermometer/dp/B000FD7G0E/ref=tag_tdp_sv_edpp_i/104-8614599-5182300

guess what - its wireless too

 

[bernardgreen]

Buy a frost stat that can be turned down to a setting below zero.

Wire this to a battery powered alarm sounder in the house.

Place stat inside freezer using thin wire that the door seal will fit round.

 

[jkmo]

Hi, on the info you gave below (for the chap who had the freezer cutting out in his shed), could you please spec a relay - I'd like to get one on line & am struggling to know what to get. Maplins? You'd probably know better.///

thanks
jkmo

You need a relay with a mains coil and a low voltage normally closed contact. Put the relay in a box, connect a length of mains lead to the coil, earth the box if it's a metal one and put a mains plug on the other end. Plug it into a socket on the same circuit as the freezer. If the power goes off the contact will close.

You can now use that relay contact to control a bell - or any other kind of alarm you like - in the house. Treat it just like a bell-push. For improved safety, connect one side of the relay contact to mains earth.

 

[mattylad]

N13AW should be OK,get the DIN socket too (N37AW)
That will prevent the need for a home made PCB.

Or similar relay, that was just the first 240v one found. Obviously if your switching more than 5A you need a bigger one.